Perianth bristles present. 2n = 38. Fruiting summer-fall. Fresh-water shores, ponds, and ditches, usually drying, usually in sandy soils, often emergent, with relatively little water-level fluctuations; 0-1000 m; Ont., Que.; Ala., Conn., Del., D.C., Ga., Ill., Ind., Ky., Maine, Md., Mass., Mich., Minn., Mo., N.J., N.Y., N.C., Pa., R.I., Tenn., Va., W.Va., Wis.